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Imagick::paintTransparentImage

(PECL imagick 2.0.0)

Imagick::paintTransparentImage — Changes any pixel that matches color with the color defined by fill

说明

Imagick::paintTransparentImage ( mixed $target , float $alpha , float $fuzz ) : bool

Changes any pixel that matches color with the color defined by fill.

参数

target: Change this target color to specified opacity value within the image.
alpha: The level of transparency: 1.0 is fully opaque and 0.0 is fully transparent.
fuzz: The fuzz member of image defines how much tolerance is acceptable to consider two colors as the same.

返回值

成功时返回 TRUE。

错误／异常

错误时抛出 ImagickException。

更新日志

版本	说明
2.1.0	Now allows a string representing the color as the first parameter. Previous versions allow only an ImagickPixel object.

User Contributed Notes

quickshiftin at gmail dot com 07-Oct-2014 04:22


Have a look at this thread on Stackoverflow for the answer regarding how to determine the max intensity of an image.



http://stackoverflow.com/questions/26239130/determine-max-possible-intensity-of-image/26240656#26240656



In short here is the code to make the $fuzz parameter behave more like you would expect (it now represents a percentage between 0-100). The $fuzz value should now be a float between 0 and 1.



class SaneImagick extends Imagick

{

    public function paintTransparentImage($target, $alpha, $fuzz)

    {

        $iQuantumDepth = pow(2, $this->getQuantumDepth()['quantumDepthLong']);

        return parent::paintTransparentImage($target, $alpha, $fuzz * $iQuantumDepth);

    }

}

alain at ocarina dot fr 17-Oct-2011 02:14


The fuzz is just working well in a range of 0 to 65535.



I suggest you to try to move fuzz on a color spectrum image.



1/ Get a color spectrum ( Google Image has a lot )



2/ Try this code :



<?php



    function fuzzTest($source, $target, $fuzz) {



        // Loads image

        $im = new Imagick($source);



        // Resizes images to make them easily comparable

        $im->resizeImage(320, 240, Imagick::FILTER_LANCZOS, 1, true);

        

        // Apply fuzz

        $im->paintTransparentImage($im->getImagePixelColor(0, 0), 0, $fuzz);

        

         // Writes image

        $im->setImageFormat('png');

        $im->writeImage($target);

        $im->destroy();

         

        return true;

     }



     for ($i = 0; ($i <= 10); $i++) {

         fuzzTest('spectrum.png', "test_{$i}.png", (6553.5 * $i));

         echo '<img src="test_' . $i . '.png" />&nbsp;';

     }

 

 ?>

Anonymous 06-Mar-2009 08:11


Actually it does seem to work just not the way expected perhaps.



Looking at the fuzz option on ImageMagick's site (http://www.imagemagick.org/script/command-line-options.php#fuzz), "The distance can be in absolute intensity units or, by appending % as a percentage of the maximum possible intensity (255, 65535, or 4294967295)."



As it requires a float, the percentage value won't work so it actually one of the max intensity values.  In my case, the images I was working with seemed to have max intensity values of 65535.  So a fuzz of 6500, for roughly 10%, seemed to do the trick.



The part that might be problematic though is how do you determine the max intensity of a color/image?  Using a static 6500 would be fine until I would have to convert an image with a max intensity other than 65535.  If it's 255 it would wipe the entire image.  Or fall far short on the fuzz with the larger value.

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Imagick::paintTransparentImage

说明

参数

返回值

错误／异常

更新日志

User Contributed Notes

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